Vacuum-tube adapter



Odi. 27 1925.

L G PACENT VACUUM TUBE ADAPTER Filed May l, 1925 "sra/TIL."

"JPL, PZA Tf INVENTOR Zou/.s- G. Pacen mfbmwwwf www@ ATTORNEY Patented Oct. 27, 1925.

UNITED. STATES A1,559,358 PATENT oFFlcE.

LOUIS G. PACENT, OF WINFIELD, NEW YORK, ASSIGNOR TO IPA-CENT ELECTIB/,IIC COM- PANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

VACUUM-TUBE ADAPTER.

Application led May 1, 1,925; Serial No. 27,126.

T0 all whom t may comem:

Be it known that I, LOUIS G. PAcEN'r, -a lcitizen of the United States, residing at Winfield, in the county of Queens, State of New York,1have invented certain new and useful Improvements in Vacuum-Tube Adapters;` and I'do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

This invention relates to adapters for electrical devices and has to do more particularly with an adapter for three electrode vacuum tubes whereby a tube ofone par` ticular style may be used with a vacuum tube socket intended primarily to receive a vacuum tube of -a different style.

The object of the present inventionv is to provide a vacuum tube adapter of substantial and altogether satisfactory construction which may be produced at very low cost.

Different types of vacuum tubes in com- .mon use dier widely in their base dimen-i a sions and in their contact prong arrangements. A base of a certain diameter and having a certain arrangement of contact prongs has come to be regarded as standard and is used quite extensively, .Most

radio receiving lsets are equipped with vacuum tube sockets4 of the standard type,- that is to say sockets deslgned to receive tubes with standard bases.

On account of their being adapted to operate economically on dry-cell batteries, a certain type of vacuum tube not equipped with a standard base has become very popular. The base of ythis latter tube is not only of smaller diameter than the standard base but the arrangement of its contact prongs is so designed that it may be very economical-` ly produced as a moldedl product-,of dielecspring, referred to herein as a leaf spring conductor, each of which extends through a slot provided in the bottom ofthe `socket member to the interior thereof where its free end is bent linto a position rwherein it may be engaged by one of the contact prongs of a vacuum tube which may be inserted in the socket.

The features of 'the invention consist int the ingenious arrangementy lof contact springs hereinafter referred toas leaf spring conductors', together with the arrangement and design of the socket member whereby the necessary cross-connections which will hereinafter be explained may be effected while maintaing a very simple form of con` struction, all the parts' of which are inexpensi-vd and the assembling operations of the simplest character.

`In the accompanying drawing- Figs. 1 and 2 are, respectively, top and bottom plan Views of a lvacuum tube adapter i-n accordance with the preferred embodiment of this invention. v

Fig. 3 is aJ-cross-sectional view of the .adapter taken along the line 3-3 of Fig. 1,

the line 1 -4 of Fig. 1,

I Fig. 5 illustrates a metal punching out of which the leaf spring conductor shown in Fig. 6 is made, l

Fig. 7 is an edgewise view of the leaf spring conductor of Fig. 6, and, Fig. 8 illustrates a-metal punching from which the leaf spring conductors, other than those shown in Figs. 5,- v6 and 7 are made.

The adapter comprises a cup like receptacle or socket member 1 made of any sultable dielectric material, as for example hard rubber or any of the well-known dielectric compositions. The outside diameter4 at 1 of the socket Ymember vis such that it' will it in a standard vacuum tube socket, while the inside diameter at 1 is such as to permit the easy insertion of a vacum tube of the type which is to be used with this particular adapter. As is well known, a three electrode vacuum tube has four contact prongs. In Fig. 2, whnch is a. bottom plan view of the adapter four contact prongsQ, 3, 4 and 5 are shown projecting from the bottom of the socket member. These contact prongs correspond with those of a standard base tube and each is labeled in such a Way as to indicate with which one of the contact springs of a standard vacuum tubel socket it is'intended to engage. The four prongs are labeled as follows: Std fil.; Std plate; Std. fil.; Std gri.d; meaning respectively standard filament; standard plate; standard filament; standard grid. In addition to the foregoing labels, the contact prongs bear the following labels, respectively: Spl plate; SpL fil.; Spl fil.;Spl. grid, meaning respectively, special plate; lspecial filament; special filament; special grid. The latter labels indicate the positions of the contact prongs of a vacuum tube of the type intended to be used with this adapter. For example it will be seen that the position of the plate contact prong of the vacuum tube intended to be used `With this adaptercorresponds with one of the filament contact prongs of a standard vacuum tube. Vice versa, it will be seen that one of the filament contact prongs of the vacuum tube intended to be used with this adapter corresponds with the plate contact prong of a standard vacuum tube. It will also be noted that the other two contact prongs of the vacuum tube intended to be used with this adapter correspond in each instance with the similar contact prong of a standard vacuum tube. The contact prong 2 engages one of the filament contact springs of the standard vacuum tube socket in which the adapter is inserted. Since the contact prong of the vacuum tube which comes directly over the vContact prong 2 leads to the plate of the'vacuum tube, the two cannot be connected together. Likewise, since the contact prong 3 connects with the plate contact spring of a standard vacuum tube socket, it cannot be connected with -the Contact prong of the vacuum tube Which comes directly over it for the reason that the latter` is connected to one side ofthe filament of the vacuum tube. Since the contact prong 2 corresponds electrically With the contact prong of the vacuum tube coming directly over contact prong 3 and Asince the contact prong 3 corresponds electrically with the contact prong of the vacuum tube directly over Contact prong 2, it follows that the electrical connections must be crossed. In other words the inside and outside connections, with respect to contact prongs 2 and 3, must be reversed. This essential reversal of connections has heretofore been accomplished in vacuum tube adapters by embedding wires or other conductors in the molded socket members and providn suitable resilient contact members insi e the socket member to which the electrical conductors were connected. A construction of that character, while it may be satisfactory from an operating standpoint, is quite costly for such a keenly competitive product.

In the structure here shown there are four slots, 6, 7, 8 and 9 extending through the bottoni ofthe molded socket member. These slots are formed in the process of molding. In addition there is a groove 10 also formed in the process of molding along the bottom of the socket member. Four contact springs 11, 12, 13 and 14 each referred to herein as a leaf spring conductor for the purpose of more definitely distinguishing from Contact springs of other types are each attached to one of the contact prongs, 2, 3, 4, 5. The method of attaching the leaf spring conductors to the contact prongs is clearly shown in the cross-sectional view of Fig. 4. Each leaf spring conductor is provided with an aperture as shown in Figs. 5 and 8 through which one of the contact prongs extends, the latter being riveted over or staked as shown for instance at 2a-the leaf lspring conductors being thereby secured to the contact prongs.

One of the fiat metal punchings out of which the leaf spring conductors 12 and 13 are made is illustrated in Fig. 8. The free ends of the leaf spring conductors projectingl within the socket member are bent over as is most clearly shown in Fig. 3 to form suitable resilient contacts for engaging the contact prongs of a vacuum tube which may be inserted in the adapter. In the operation of assembling, the fiat punchings are each first given a right angle bend; passed through one of theslots in the socket ineinber and secured to one of the contact prongs in the manner previously described.

For the purpose of accomplishing the .necessary cross-connections leaf spring conductor 11 which is attached to contact prong 3 has its free end bent into a position where- 1n it lies over contact prong 2 instead of its own contact prong 3. Leaf spring conductor 14 is of different form than the others as is `clearly illustrated in Figs. 5, 6 and 7, whereinFig. 5 is a blank and Figs. 6 and 7 are two views showing the leaf spring conductor in final forni. Leaf spring conductor 14 is secured to contact prong 2. It is formed so as to extend along and within the groove 10' to the slot 7 through which it extends upwardly into the recess within the socket member wherein its free end is lient into a position lying over contact prong 3. y

The socket member 1 is formed with a bayonet-lock joint at 1, adapted to receive and cooperate with the pin ordinarily provided Von the base of a vacuum tube for holding vit in place in the adapter. The socket member is also formed with a small pin hole at 1d into which a lock pin 15 is Cal bayonet-lock joint of a standard vacuum tube socket into which the adapter is in tended `to be inserted.

lFrom a careful consideration of the several views of the 'drawing the outstanding` simplicity of the structure illustrated will be noted. The mold required to form thel socket member is lexceedingly simple due to the absence of any intricate inserts which are diicult to hold in place Iduring the y,

-molded cup like socket member of dielectric molding process. In fact the only inserts are the contact prongs 2,' 3, 4, and 5 which. may be very easily supported Vin the mold. When the socket member comes from the mold all that remains to be done is to insert the locking pin 15 and attach the` leaf spring conductors. The latter are each given a right angle bend With av suitable tool., slipped overtheir respective contact prongs and the latter' staked torigidly secure the leaf spring` conductors 1n place.. The free end ofthe leaf spring conductors are then bent as .clearly shown in Figs. 3, 4, 6 and 7.

Allthe metal parts are simple screw machine and punch press products which may be readily produced in large lquantities at small labor cost and the assembling operations are vso simple as to lrequire the employment of only the mostunskilled labor to perform-while the resultant product may lbemof the highest quality, depending only upon the materials selected.

The particular adapter illustrated inthe drawing and described herein,. although representing the preferred embodiment of the invention is not to be construed as, representing the onl construction 'possible within the scope o the invention.` On the contrary the' invention is, in fact, capable-v of being embodied in a number of modified` forms and should not be considered as limlitedexcept by the terms o f the appended claims.

I claim:

' 1. A vacuum tube adapter comprising acup like socket member, a lplurality yof cone tact prongs attached to and projecting from the ibottom of said socket member and arrangedv to engage the resilient contacts of a vacuum tube socket into which said adapter may be inserted, a plurality of slots extending through the bottom of said socket member;l a plurality of leaf sprin conductorsl -each of which is attached, ind1vidually, to

lone of said contact prongs and extends individually through one of said slots to the interior of saidv socket member, the end portion of each of said leaf sprin conductors which is inside said socket mem r being so positioned as to engage, individually, one of the contact prongs of a vacuum tube which may be\inserted in said socket member, the arrangement being such that each contact prong of the vacuum tube is electrically connected through one of Said leaf spring. conductors, individually, to the proper one of said contact prongs forming a part of said adapter.

2. A vacuum tube adapter comprising a material, a plurality of contact prongs embedded'l in 'and projecting from the bottom of said socket member and, arranged to engage the resilient'contacts of a vacuum tube socket into which'said adapter may be inserted, av plurality of slots extending through the bottom of said socket member, a plurality of leaf spring conductors each of which is staked individually to one of said contact prongs and extends, indi vidually, through one of said slots to the interior of said socket member,l the end portion of leach of said leaf spring conductors which is inside "said .socket member being so positioned' as to engage individually, one of the contact prongs of a vacuum tube which may be inserted in said socket member, the arrangement being such that each contact pron of the vacuum tube iselectrically connecte through one of said' leaf spring conductors, individually, to the proper one of said contact vprongs forming va part of said ada ter.

3. A vacuum tu e adapter comprising a cup like socket member, the bottom of said socket member being `formedwith a groove and rovidedwith a plurality of slots .ex-

tending therethrough, a plurality of contact prongs'attached to and extendin from the ottom of said socket member, a eaf spring conductor attached to o'ne of said contact prongs and extending along and within said groove to one of saidslots, thence through said last mentioned Slot to the interior of said socket member, the free end portion of said leaf spring conductorwithin said socket member being disposed in a position wherein' it is engageable by the contact pron of a vacuum tube corresponding electrica y to the said contact prong to which said leaf spring conductor is attached, and a plurality of additional leaf spring con- `ductors each attached individually to one of said contact prongs and each extending, individually, through one of said slots to the interior of said socket member.

In testimony whereof I affix my signature.

LoUrs G. PAcnzNr.'

Cil 

